The present invention generally relates to irrigation systems. More specifically, the present invention relates to a system and method for providing reliable control of irrigation systems.
FIG. 1 is a simplified functional block diagram showing the configuration of a typical irrigation system 10. The irrigation system 10 typically includes a central control 12, a number of irrigation controllers 14 located at remote locations, a communication network 18 used by the central control 12 to communicate with the irrigation controllers 14, and a number of valves 16 each controllable by an irrigation controller 14. Each valve 16 is used to provide irrigation, when necessary, to a designated area.
The irrigation system 10 generally operates as follows. Based on information maintained by the central control 12, the central control 12 communicates with the appropriate irrigation controllers 14. Upon receiving communication from the central control 12, the irrigation controllers 14 cause the corresponding valves 16 to deliver the proper amount of irrigation to designated areas. The actions of the central control 12 can be controlled in either an automated or a manual manner. In other words, the central control 12 can be controlled either by automated control logic implemented via, for example, a computer software program, or by a human system administrator.
The communication network 18 is responsible for handling communications between the central control 12 and the irrigation controllers 14. Typically, the communication network 18 uses a single communication channel to achieve communications between the central control 12 and the irrigation controllers 14. The single communication channel can be, for example, a particular radio frequency. When communication between the central control 12 and the irrigation controllers 14 is desired, the central control 12 uses the communication network 18 to transmit or broadcast messages to the irrigation controllers 14 via the single communication channel. Each irrigation controller 14 periodically monitors the single communication channel and, upon detecting and receiving messages from the single communication channel, takes appropriate action in accordance with the messages received.
Transmitting signals via a single communication channel in a communication network 18, however, is often unreliable. For example, the communication network 18 may not be equally effective in delivering messages to all different areas where the irrigation controllers 14 are located. In another example, the communication network 18 used to transmit or broadcast messages may malfunction or otherwise become defective. As a result, messages transmitted by the central control 12 may never be received by the irrigation controllers 14.
Hence, it would be desirable to provide a method and system that is capable of providing reliable communications to facilitate control of an irrigation system.